Technical Field
The present invention relates to a kneading apparatus, and more specifically to a kneading apparatus in which cubic paddles that are provided on two rotary shafts are caused to rotate to convey every kind of materials while being kneaded.
Background Art
Conventionally, such a kneading apparatus (mixer) has been used in kneading materials and those with liquids added thereto, the materials, for example, including dehydrated sludge, incinerated or collected dust, other types of dust mixed with a solidifier such as cement, or powdery or granular materials such as fertilizer.
Conventionally, such a kneading apparatus is known, as is, for example, disclosed in Patent Document 1, in which two rotary shafts each having a plurality of rods erected so as to be arranged helically with an inverse helix are caused to rotate at unequal speeds to knead and convey materials in one direction. In such a kneading apparatus, the rods are arranged so that the distal ends thereof come in proximity to the external peripheral surface of the facing rotary shaft. Causing the two rotary shafts to rotate makes it possible to scrape off the kneaded object that has adhered to the external peripheral surface of the other rotary shaft, thus performing self-cleaning. Patent Document 1 discloses that such rods may be replaced with flat plate paddles (paragraph [0045]).
Patent Document 2 also discloses a kneading apparatus including a first rotary shaft having a plurality of paddles as stirring members vertically provided on the external periphery thereof so as to be arranged helically at a predetermined helical pitch and at predetermined angular pitch intervals, and a second rotary shaft having a plurality of similar paddles vertically provided so as to be arranged helically with an inverse helix from that of the first rotary shaft at a predetermined helical pitch and at predetermined angular pitch intervals. Also in this kneading apparatus, the first and second rotary shafts are caused to rotate in opposite directions at unequal speeds. The helical pitch ratio of the first and second rotary shafts is set so as to be the inverse of the rotational speed ratio of the first and second rotary shafts, and the angular pitch ratio of the paddles of the first and second rotary shafts so as to be the same as the rotational speed ratio of the first and second rotary shafts.